When my children were in school, I paid for their lunch two weeks in advance. The lunch price was the same every day, regardless of what was served/eaten. Because we received the preplanned menu, my children were able to decide if they were going to have the hot lunch or bring a lunch from home because they did not like every single lunch menu item.
Perhaps if you can do the same, you know what to expect for lunch or avoid for lunch. On the days you don't like what the cafeteria is serving, bring your own lunch.
Not until my son graduated did I find out something very funny. You see, I love making sandwiches and made them often for him to eat at school. Come to find out, he was selling either half of his sandwich or the whole thing to kids who did not like what was being served in the cafeteria. On days that the cafeteria was serving unpopular foods, he asked me to make him a sandwich and a half and end up selling them, making a pretty good profit!! We laugh about that every now and again!
And, yes, four dollars for beans and rice is pathetic. That is a $1.25 meal.